Application of an organic thin-film transistor (TFT) to a portable computer or a planar display has been developed. For example, in WO 01/47043, technique of manufacturing an organic thin-film transistor employing only polymer is disclosed, and a method of manufacturing a transistor employing a simple method such as an ink jet method or a coating method is proposed.
As an important step for manufacturing an organic TFT, there is a step of forming a channel pattern with high precision. In the patent described above, Japanese Patent O.P.I. Publication Nos. 10-190001 and 2000-307172, a gold layer formed according to a vacuum deposition method is subjected to patterning employing photolithography to form a channel portion. However, the above technique comprises a deposition process under vacuum and complex manufacturing steps, and needs an expensive manufacturing facility, resulting in cost increase.
In WO 01/47043 and WO 00/79617 is disclosed a method of forming an electrically conductive polymer pattern employing an ink jet method. However, this method has problem in that the electrically conductive polymer has high electric resistance, and does not provide high electric current.
In Japanese Patent O.P.I. Publication Nos. 2000-239853 are disclosed a method, which coats a metal particle dispersion on a substrate and heat-fuses the metal particles to form a metal film on the substrate, and a method, in which patterning is carried out employing a screen printing method. However, in this patent there is no disclosure regarding manufacture of an organic thin-film transistor.